Topics

1

General / [Threading] findPath

« on: December 20, 2012, 08:37:54 pm »

Hello,

Currently I have a pathfind algorithm for a set of enemies, which uses quite alot of resources and CPU time. So before I ran the algorithm each frame, causing alot of FPS lag. So I made a class with a thread, that takes care of the calculation.
So here's a sketch of what I have:
Npc class

class NPC {
public:
      void setPath(std::vector<Node*>);
      void walkPath();
      ....
private:
     std::vector<Node*> m_path;
}

void walkPath() {
   if(m_path.size() >= 2) {
        walkToNode(m_path.at(1));
}
 

Now for each new NPC I create, I create a thread managing the path calculations
Thread

class Thread {
private:
    m_player;
    m_enemy;
}

void Thread::run() {
    sf::Mutex mutex;
   
    mutex.lock();
   
    std::vector<Node*> path = findPath(m_enemy, m_player);
    m_enemy->setPath(path);
   
    mutex.unlock();
}
 

that's a pretty rought sketch, but you see what I mean.
Also, with the walkPath method, I just always walk to the second element because, by the time the enemy gets there, i'll probably have a new path, calculated from the node the enemy arrives on and just goes from there

Right now, the program just crashes when I use the thread instead of calculating the path each frame due to a segmentation fault. I don't know what I'm doing wrong...

Please help me, thanks!

2

General / [Weird] Linking problems

« on: December 12, 2012, 05:13:50 pm »

Hello, I'm trying out SFML for the first time and everything worked fine, with the example code. So then I started integrating it with my project and came across a really weird problem. So I started with this piece of code:

#include <SFML/Window.hpp>

/*
 * @brief Main function, entry point
 *
 * @return      Exit code
 */

int main() {
        sf::Window window;
        return 0;
}
 

And got the following errors:

/usr/local/lib/libsfml-window.so: undefined reference to `sf::Clock::Reset()'
/usr/local/lib/libsfml-window.so: undefined reference to `sf::Unicode::UTF8Offsets'
/usr/local/lib/libsfml-window.so: undefined reference to `sf::Clock::Clock()'
/usr/local/lib/libsfml-window.so: undefined reference to `sf::Clock::GetElapsedTime() const'
/usr/local/lib/libsfml-window.so: undefined reference to `sf::Unicode::UTF8TrailingBytes'
/usr/local/lib/libsfml-window.so: undefined reference to `sf::Sleep(float)'

Now, I 'fixed' it like so:

#include <SFML/Window.hpp>

/*
 * @brief Main function, entry point
 *
 * @return      Exit code
 */

int main() {
        sf::Clock testClock; //this fixed the problem???!!!!
        sf::Window window;
        return 0;
}
 

it builds fine, no errors at all...

Someone please help me?

By the way, I'm using SFML 1. 6 on an Ubuntu machine